Every year, millions of old smartphones, computers, toys and other electronic devices are thrown away, creating a growing mountain of electronic waste.
One of the biggest challenges is that the printed circuit boards (PCBs) inside these devices are difficult to recycle because they are made from strong plastic materials reinforced with glass fibers.
These materials can last for many years after being discarded.
Now, researchers at TU Bergakademie Freiberg in Germany have developed a new type of circuit board that could help solve this problem.
Instead of using fossil-based plastics, they created a biodegradable circuit board from the waste left behind after industrial citric acid production.
Their study, published in the journal Cleaner Materials, shows that this unusual material could become a more environmentally friendly option for some electronic products.
The researchers used the mycelium of the fungus Aspergillus niger.
Mycelium is the thread-like network that forms the main body of a fungus. Large amounts of this fungal material are produced as a waste product during the manufacture of citric acid, which is widely used in foods, drinks and many household products.
Rather than throwing this fungal waste away, the team turned it into a plastic-like material using a simple process. The mycelium was placed into molds and then dried in the air, creating rigid boards about half a centimeter thick. The finished material has a density similar to that of conventional printed circuit boards.
To show that the boards could actually be used for electronics, the researchers added electronic circuits using standard manufacturing methods. They successfully attached electronic components to the fungal boards through printing, etching and manual soldering.
Laboratory tests showed that the new material has good strength and can withstand heat reasonably well.
While its electrical performance is not yet as good as today’s commercial circuit boards, it is already suitable for simpler electronic devices.
The researchers believe it could be used in products such as environmental sensors, electronic toys, educational devices and other low-frequency electronics where extremely high performance is not required.
More testing is still needed before the material can compete directly with traditional circuit boards. For example, scientists want to improve its resistance to water and ensure it meets international industry standards for electronic components.
The need for better materials is becoming increasingly urgent. According to the Global E-waste Monitor, the world is expected to produce around 82 million metric tons of electronic waste every year by 2030. Much of that waste contains printed circuit boards that are difficult to recycle and often end up in landfills.
One of the biggest advantages of the new fungal board is what happens after it is no longer needed. The board itself is fully biodegradable and can be safely broken down in water, while valuable electronic components attached to it can potentially be recovered and reused.
The researchers also calculated the environmental impact of the new material across its entire life cycle. They found that producing the fungal circuit board generates up to 56% less carbon dioxide than manufacturing a conventional PCB.
By turning an industrial waste product into a useful electronic material, the team hopes to support the development of a more sustainable electronics industry.
Their work shows that future electronic devices may not only perform well but also leave behind far less waste when they reach the end of their lives.
